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A230906 Number of nX4 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero 1
0, 26, 152, 802, 4308, 23614, 130178, 718750, 3970738, 21941252, 121252356, 670093980, 3703301746, 20466628218, 113111135842, 625122784014, 3454822416978, 19093535079990, 105522984179168, 583187006699888 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A230910

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 20*a(n-1) -174*a(n-2) +877*a(n-3) -2835*a(n-4) +6037*a(n-5) -8100*a(n-6) +5354*a(n-7) +1632*a(n-8) -5940*a(n-9) +3068*a(n-10) +2069*a(n-11) -3724*a(n-12) +2559*a(n-13) +882*a(n-14) -5020*a(n-15) +2708*a(n-16) +3962*a(n-17) -3859*a(n-18) -890*a(n-19) +2032*a(n-20) -318*a(n-21) -643*a(n-22) +197*a(n-23) +81*a(n-24) -10*a(n-25) -35*a(n-26) +15*a(n-27) -a(n-28) for n>31

EXAMPLE

Some solutions for n=4

..0..1..0..3....0..2..0..3....0..2..1..0....0..2..3..1....0..1..0..1

..2..3..2..1....1..3..1..2....1..3..2..3....1..0..2..3....2..3..2..0

..0..1..3..0....0..2..0..3....2..0..1..0....3..1..0..1....1..0..3..2

..3..0..2..3....1..3..1..2....3..2..3..2....0..3..2..0....3..2..1..0

CROSSREFS

Sequence in context: A248465 A014552 A192289 * A232585 A042314 A280213

Adjacent sequences:  A230903 A230904 A230905 * A230907 A230908 A230909

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 01 2013

STATUS

approved

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Last modified November 19 08:40 EST 2018. Contains 317347 sequences. (Running on oeis4.)